Calories are calories. Losing weight is simple math—you eat fewer calories than you expend. That’s true…kind of. There is another part of the equation that isn’t talked about as much, but scientists are beginning to open up the discussion as research advances. It is called the thermic effect of food.

Every macronutrient (protein, carbohydrate, and fat) you eat has to be digested, transported, absorbed and stored by the body. This requires work by your body and can increase your baseline metabolism for up to several hours after a meal (depending on the type of food).

What you eat does matter because all macronutrients are not created equally

They can affect your energy expenditure in significantly different ways. The numbers below show just how much your metabolism is increased with each macro:

Fat: 0 to 3%

Carbohydrates: 5 to 10%

Protein: 20 to 30%

Let’s take this to the real world with an example. Say we have two BFFs going to a football game and stop for a snack. One decides to have a large chocolate covered donut as a snack and the other some beef jerky. Just by choosing a protein heavy food BFF #2 is making his body work more, increasing his metabolism, and burning calories. When trying to lose weight this difference in choice of calories is significant.

How does this help someone seeking to lose fat? You can optimize weight loss by manipulating the macronutrients to include high levels of protein with moderate carbohydrates and fats. Eating five or more small meals with protein also keeps your body working throughout the day.

Protein is pretty freaking awesome because not only does it increase your metabolism just be ingesting it, but it also helps to maintain muscle. Whenever you’re in a calorie deficit increasing your protein intake will help preserve your muscle mass so that you’re losing fat and not muscle.

Yes, what you eat matters. Choose wisely, my friends.